Mechanical Properties and Triobological Behavior of Stir Cast Al-6063 Alloy Based Hybrid Composite

India is one of the developing countries that need to face the many challenges in automotive industry. In industries usage of heavier materials are replaced by aluminium alloys because of its good properties. The objective of this work is investigating the influence of quarry gravel powder (QGP), silicon carbide (Sic) and fly ash (FA) particles of fraction percentage on the mechanical properties and wear behavior of Al6063 based alloy metal matrix composites. The abrasive ceramic particles, fly ash and gravel powder reinforced in the metal matrix are the cause of improvement in mechanical and tribological properties of the materials. The al 6063 metal matrix hybrid composite consist of 4 wt%, 6 wt%, and 8 wt% QGP-SiC–FA respectively was processed by using stir casting technique procedure. Tribological Wear behavior of the developed hybrid composites was characterized at different loads, sliding velocities and distances using pin-on-disc method. The experimental results are discuss that the applied load and reinforcement of wt% are the major parameters influencing the specific wear rate for all samples, followed by weight fraction of reinforcement, sliding velocity and sliding distance

The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation

Abstract Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation

Quality of Care: The Role of Disease Registries

The origin of cancer registries was to create clinical surveys and perform patient follow-up, the objective being to bring surgical patients back to the doctor periodically to identify recurrences. Over the past 60 years, cancer registries have continued to compile patient care data and perform patient follow-up. However, over the past decade, emphasis has been placed on the direct involvement of the cancer registry in monitoring quality of care. In contrast, stroke registries monitor the quality of care for patients, but do not follow them periodically to identify recurrences. The biology of these diseases is an intricate part of the different roles played by both types of registries, yet each has a page to take from the other\u27s book. This article examines the manner in which these registries operate to improve the quality of patient care